1. Field of the Invention:
The invention resides in the field of spectrometers and is more particularly related to detector systems for echelle grating spectrometers.
2. Description of the Prior Art:
Detector systems for prior art spectrometers known to the inventors are of two types. Both employ detectors which are mechanically mounted in a fixed position. The first type consists of those in which a single detector is arranged to respond to various wavelengths as they are brought into the field of view of the detector by manipulation of the spectrometer grating, optical components within the spectrometer, or shifting apertures which sequentially block all but selected wavelengths.
Alternatively, a plurality of detectors are employed to simultaneously detect a plurality of wavelengths as determined by multiple aperture plate positioned to intercept a spectral array dispersed by a grating. The plate is necessarily limited to a selected number of apertures far less than the dispersing capability of the spectrometer. Such a system is shown in use with an echelle grating spectrometer in U.S. Pat. No. 4,049,353, Missio.
In contrast, the present invention employs a single scannable detector in conjunction with an aperture plate which may contain apertures corresponding to all of the wavelengths of interest. As a result, electronic and mechanical techniques may be used to perform selected patterns of sequential measurements by moving the detector rather than any of the optical components of the system. Additionally, the use of a single detector insures a continuous known uniform response to all wavelengths and greatly facilitates calibration of the system. Further, since the scannable detector is moveable by nature, it may be completely removed from the field of the aperture plate and an array of detectors with a masking aperture plate for multiple simultaneous measurements substituted therefore.